Laser Level Square is an easy to use leveling tool. Projects horizontal and vertical laser "chalk lines" on surfaces. Dual diodes for making 90 degree laser beams on any surfaces. Two suction cups allow the laser level square to be mounted onto the surfaces alignment guide for 90-degree layout-calculate and turning angles in 5-degree increments. Kindly noted: the angle of the laser line can be changed according to the angle scale, saving your time of measurement and marking. Ideal for a variety of uses, including flooring, tile layout, paneling, wallpapering, stenciling, wainscoting, finish carpentry, outlet and switch layout, wall stud layout and partition installation. Specification: Dimensions (L x W x H):150 x 73 x 50mm Wavelength: 630-670nm Power output max 5mw ; Accuracy: 1mm/3m Available distance: 16m Battery type: 3 AAA1.5V batteries(Not included) Operation temperature: -10~50 Applications: make 90 degrees laser beam on any surfaces, to install home decorations, woodworking decorations, tiles and draw beelines Kindly noted: the angle of the laser line can be changed according to the angle scale, saving your time of measurement and marking. During packaging or transportation, it is possible that the gradienter is adjusted, affecting the angle of the laser line. Package includes:Square laser level x 1